Guided 3D Display Adaptation

ABSTRACT

A 3D display is characterized by a quality of viewing experience (QVE) mapping which represents a display-specific input-output relationship between input depth values and output QVE values. Examples of QVE mappings based on a metric of “viewing blur” are presented. Given reference depth data generated for a reference display and a representation of an artist&#39;s mapping function, which represents an input-output relationship between original input depth data and QVE data generated using a QVE mapping for a reference display, a decoder may reconstruct the reference depth data and apply an inverse QVE mapping for a target display to generate output depth data optimized for the target display.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/807,672, filed on 2 Apr. 2013, incorporated herein by reference inits entirety.

TECHNOLOGY

The present invention relates generally to stereoscopic images anddisplays. More particularly, an embodiment of the present inventionrelates to the guided rendering of stereoscopic images onto stereoscopicor auto-stereoscopic displays.

BACKGROUND OF THE INVENTION

3D video systems garner great interest for enhancing a consumer'sexperience, whether at the cinema or in the home. These systems usestereoscopic or auto-stereoscopic methods of presentation, including:

(i) anaglyph—provides left/right eye separation by filtering the lightthrough a two color filter, commonly red for one eye, and cyan for theother eye;

(ii) linear polarization—provides separation at the projector byfiltering the left eye through a linear polarizer (commonly) orientedvertically, and filtering the right eye image through a linear polarizeroriented horizontally;

(iii) circular polarization—provides separation at the projector byfiltering the left eye image through a (commonly) left handed circularpolarizer, and filtering the right eye image through a right handedcircular polarizer;

(iv) shutter glasses—provides separation by multiplexing the left andright images in time, and

(v) spectral separation—provides separation at the projector byfiltering the left and right eye spectrally where the left and right eyeeach receives a complementary portion of the red, green, and bluespectrums.

Most of the 3D displays available in the market today are stereoscopicTVs, requiring the user to wear special 3D glasses in order toexperience the 3D effect. Delivery of 3D content to these displays onlyrequires carrying two separate views: a left view and a right view.Auto-stereoscopic (glasses-free) or multi-view displays are in thehorizon. These displays provide some amount of motion parallax; theviewer can move his/her head around as if they are viewing objects fromdifferent angles as they move around.

Traditional stereoscopic displays provide a single 3D view; however,auto-stereoscopic displays are required to provide multiple views suchas five views, nine views, 28 views, etc., based on the design of thedisplay. When regular stereoscopic content is provided toauto-stereoscopic displays, the displays extract depth maps and createor render multiple views based on these depth maps. As used herein, theterm “depth map” denotes an image or other bit-stream that containsinformation related to the distance of the surfaces of scene objectsfrom a viewpoint. A depth map can be readily converted to a disparitymap, and vice versa, and in the context of this document the terms depthmap and disparity map are the same and inter-changeable.

3D content optimized for a certain target display (e.g., the screen of amovie theater) may appear differently on a stereoscopic or multi-viewHDTV at home. The 3D viewing experience may also differ depending on thedisplay's screen size, multi-view technology, and other parameters. Asappreciated by the inventors here, it is desirable to develop improvedtechniques for rendering stereoscopic content on 3D displays, whilepreserving the original creator's (e.g., the director's) artisticintent.

The approaches described in this section are approaches that could bepursued, but not necessarily approaches that have been previouslyconceived or pursued. Therefore, unless otherwise indicated, it shouldnot be assumed that any of the approaches described in this sectionqualify as prior art merely by virtue of their inclusion in thissection. Similarly, issues identified with respect to one or moreapproaches should not assume to have been recognized in any prior art onthe basis of this section, unless otherwise indicated.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention is illustrated by way of example,and not in way by limitation, in the figures of the accompanyingdrawings and in which like reference numerals refer to similar elementsand in which:

FIG. 1A and FIG. 1B depict examples of quality of viewing experience(QVE) mappings for three auto-stereoscopic displays according to anembodiment;

FIG. 2 depicts an example process to determine the QVE mapping of atarget display according to an embodiment;

FIG. 3 depicts example target test images to determine the QVE mappingof a target display according to an embodiment;

FIG. 4A and FIG. 4B depict example processes for guided 3D displayadaptation according to embodiments; and

FIG. 5 depicts an example process for 3D display emulation according toan embodiment.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Guided 3D display adaption techniques for displaying stereoscopic imageson stereoscopic and multi-view displays are described herein. A displayis characterized using a quality of viewing experience (QVE) mapping(e.g., a mapping function or input-output curve) which represents aviewing experience metric on the particular 3D display as a function ofinput disparity or depth data. The mapping of depth data from areference 3D display to any 3D display may be represented using a depthrange conversion function and metadata created in response to the QVEmapping of the reference display and the director's original artisticintent. In the following description, for the purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be apparent, however,that the present invention may be practiced without these specificdetails. In other instances, well-known structures and devices are notdescribed in exhaustive detail in order to avoid unnecessarily obscuringthe present invention.

Overview

Example embodiments described herein relate to guided 3D displayadaptation techniques for displaying stereoscopic images on stereoscopicand multi-view displays. 3D displays are characterized by a quality ofviewing experience (QVE) mapping which represents a viewing experiencemetric on the particular 3D display as a function of input disparity ordepth data. Examples of QVE mapping functions based on a metric of“viewing blur” are presented. Given reference depth data generated frominput depth data for a reference display, and a representation of anartist's mapping function, which represents an input-output relationshipbetween the input depth data and QVE data generated using a referencedisplay QVE mapping, a decoder may reconstruct the reference depth dataand apply an inverse QVE mapping for a target display to generate outputdepth data for the target display that also preserves the originalartist's intent.

In another embodiment, a 3D display QVE mapping function is generated bydisplaying a stereo image at a known depth or disparity, capturing thedisplayed image with a 2D camera, and analyzing the captured 2D image togenerate a corresponding QVE value. In an embodiment, the correspondingQVE value is a function of the standard deviation of a Gaussian blurfilter, which given the test image as an input generates an output thatis closest to the captured 2D image according to a given criterion.

In another embodiment, original input depth data for a stereoscopicimage are received. In response to the original input depth data, usinga reference display, reference depth map data are being generated. Adepth range conversion function may represent the input-outputrelationship between the input depth data and the reference output depthdata. In response to the reference depth map data and the referencedisplay QVE mapping, quality of viewing experience (QVE) data aregenerated. An artist's mapping function, which represents aninput-output relationship between the input depth data and the QVE data,is generated and is transmitted as metadata to a receiver together witheither the reference depth map data or the original input depth data;

In another embodiment, a 3D display emulation system accesses originalinput depth data for a stereoscopic image. In response to the originalinput depth data, using a reference display, reference depth map dataare being generated. In response to the reference depth map data and thereference display QVE mapping, quality of viewing experience (QVE) dataare generated. A target display to be emulated is selected amongdifferent models of target displays and the QVE data are applied to aninverse QVE mapping for the emulated target display to generate targetdepth data for the emulated target display, wherein the inverse QVEmapping for the emulated target display represents an input-outputrelationship between input QVE values and output depth values asdetermined for the emulated target display.

Example Quality of Viewing Experience Mapping

In stereoscopic content production and display, the original release istypically optimized for a certain target display size and viewingdistance and then it is delivered using a bitstream that includes imagedata and depth or disparity data. For example, live sports broadcast maybe optimized for delivery to home 3D HDTVs, while theatrical releasesmay be optimized for 3D movie-theater projectors. As used herein, theterm ‘disparity’ denotes the difference in distance between the locationof an object in a left view and a right view of a stereoscopic image. Instereo video imaging, disparity typically represents the horizontalshift (e.g., to the left or to the right) of an image feature in oneview (e.g., the left image) when viewed in the other view (e.g., theright image). For example, a point located in the horizontal positionsh_(L) in the left image and h_(R) in the right image may be denoted ashaving a disparity of h_(L)−h_(R) pixels.

Disparity data may also be represented as depth or “input Z” data,typically represented as grayscale data in the [0,255] range for 8-bit,although alternative representations are also possible. In anembodiment, given an input disparity D, and d_(min) and d_(max)disparity limit values as will be defined below, a disparity to depthtransformation (Z) in the range [0,255] may be defined as:

$\begin{matrix}{Z = {{round}\mspace{14mu} {\left( {\left( {D - d_{\min}} \right)\left( \frac{255}{d_{\max} - d_{{mi}n}} \right)} \right).}}} & (1)\end{matrix}$

In equation (1), d_(min) denotes the input disparity value in luminancepixels of the texture that corresponds to a decoded depth value Z=0.Negative values of d_(min) relate to a virtual location in front of thescreen plane. Similarly, d_(max) defines the input disparity value inluminance pixels of the texture view that corresponds with a decodeddepth value Z=255. The value of d_(max) should be greater than d_(min).Together d_(min) and d_(max) define the input disparity range to whichthe decoded depth values should be uniformly mapped. Given Z, d_(min),and d_(max) values, a reverse Z to D mapping may also be derived fromequation (1) as

$\begin{matrix}{D = {\frac{Z\left( {d_{\max} - d_{\min}} \right)}{255} + d_{\min.}}} & (2)\end{matrix}$

Note that d_(min) and d_(max) values may vary on a per frame, per regionof interest, per scene, or other suitable basis. For example, in a firstscene the disparity range may be in the range [−10, 30] while in asecond scene the disparity may be in the range [−50, 200]. These d_(min)and d_(max) values may be communicated to downstream processors or atarget receiver (such as a set-top box) using metadata or ancillarybitstream data.

Delivering full resolution video and good quality depth/disparity mapdata is essential for both stereoscopic and auto-stereoscopic displays.Good quality disparity maps can be created during the 3D contentcreation process either manually or automatically. These disparity mapsare typically created for a specific display type (e.g. a 3D cinemaprojector) and may not be suitable for other 3D displays (e.g., aportable gaming device or tablet with a 3D display or a home 3D HDTV)and hence need to be modified. For example, if a disparity map iscreated for a glasses-based cinema projector or glasses-based stereo TV,the disparity range can be more than what can be handled by a typicalglasses-free auto stereoscopic (AS3D) display. For example, thesedisparity maps may not use the AS3D display's limited capabilities in anoptimal fashion. Furthermore, AS3D displays are made by differentmanufacturers and have different characteristics from one another.Hence, given a reference stereoscopic image, there is a need to generatedisparity maps which can be used universally across different types of3D displays while also preserving the original director's intent.

According to an embodiment, a first step towards a solution to thisproblem is to define a mapping or function that uniquely characterizesthe quality of viewing experience (QVE) on a particular display as afunction of the disparity or depth of input data. In an embodiment,without loss of generality, the main parameter considered forrepresenting the quality of viewing experience is “viewing blur”;however, it can be expanded to include other viewing factors, such asimage ghosting or crosstalk, or image flipping (i.e., wiping effect) atthe cone boundaries of a multi-view AS3D display.

In FIG. 1A, 100 depicts examples of QVE mappings (110, 120, 130) forthree different auto-stereoscopic displays according to an exampleembodiment. Measured diagonally, 100 depicts QVE mappings for an 11inches display (110), a 23 inches display (120), and a 56 inches display(130). As will explained in more detail later, in this embodiment, they-axis of 100 provides a measure of output blur as computed for inputimages with depth values ranging between 0 and 255.

FIG. 2 depicts an example process to derive the QVE mapping (e.g., 110,120, or 130) for a specific display according to an embodiment. Asdepicted in FIG. 2, in step 205, the process starts by setting up thedisplay under consideration and a camera to capture test imagesprojected onto the display. Set-up comprises calibrating the display andplacing the camera at a typical viewing distance for the target display(e.g., 1.5 feet for an 11 inch display). For auto-stereoscopic displays,the camera is also placed at the center of the display's viewing cone.Given a target depth range (e.g., 0 to 255) a set of test images (225)is prepared for each depth value under testing. Note thatdisparity-related parameters (e.g., d_(min) and d_(max)) may vary foreach display. In an embodiment, each of the test images 225 may comprisea series of vertical lines of variable width. For example, the verticallines may represent a spatial 2-D sinusoid wave plotted at variousfrequencies. Examples of such test patterns are depicted in FIG. 3.

Processing loop 250 is repeated for each depth value under considerationand includes the following steps: (a) In step 210, a target test imageis displayed. (b) In step 215, the displayed image is captured by thecamera as a 2D image. Because of the embedded disparity in the testimage, it is expected that the captured image by the camera will be ofworse visual quality (e.g., more blurry) than the original test image.Finally, (c) in step 220, the captured image is analyzed and is assigneda QVE metric. The QVE metric could be either subjective or objective,and is assigned a numerical value according to some pre-determinedcriterion. In one embodiment (100), an objective QVE metric between 0and 4 represents the standard deviation σ of a Gaussian blur filter thatyields an output of equivalent blur as the input disparity. An exampleof computing such a metric is discussed next.

Given that “visual blur” is considered the main parameter of the visualexperience factor, each test image (225) may be blurred using a varietyof blur filters (230), such as a set of Gaussian blur filters or anyother type of low-pass or blur filters. In an embodiment, each of theseGaussian blur filters may have the same size kernel but a differentstandard deviation σ parameter (e.g., 5 between 0.3 and 4). Then, instep 220, each captured image (215) is compared against the set of allblurred images (230) according to an error criterion, such as thecommonly used SNR (signal-to-noise ratio) and Peak-SNR criteria. Then,for a given depth, the output QVE metric (e.g., QVE=3.0) may be definedas the standard deviation of the blur filter for which its output bestmatches the captured test image according to the given criterion.

As it will be further discussed later, given a QVE mapping (e.g.f_(TQ)(Z) 110), in some embodiments it may be desirable to apply itsinverse f_(Z)(Q)=f_(TQ) ⁻¹(Z), so that for a given QVE value (e.g., Q)one can determine the corresponding depth Z=f_(Z)(Q). However, therepresentation of QVE mappings as depicted in FIG. 1A is not suitablefor defining an inverse since a single QVE value may be mapped into twodifferent depth values. Given a QVE mapping f_(TQ)(Z) as depicted inFIG. 1A, in some embodiments, an invertible f_(Q)(Z) mapping functionmay be derived as follows:

$\begin{matrix}{{f_{Q}(Z)} = \left\{ \begin{matrix}{{f_{TQ}(Z)},} & {{{if}\mspace{14mu} D} \geq 0} \\{{- {f_{TQ}(Z)}},} & {{{if}\mspace{14mu} D} < 0}\end{matrix} \right.} & (3)\end{matrix}$

where for a given depth Z, d_(min) and d_(max), disparity D may becomputed using equation (2). For the family of f_(TQ)(Z) mappingsdepicted in FIG. 1A, FIG. 1B depicts example corresponding f_(Q)(Z)mappings.

Applications to Guided Display Adaptation

FIG. 4A depicts an example guided display adaptation process for 3Ddisplays according to an embodiment. Original content 405 comprisesimage and depth or disparity data created for an original releasetargeting an original target display (e.g., a cinema projector). In manycases of interest, this content needs to be reprocessed to generateanother release targeting different types of displays.

Step 410 denotes a typical post-production stage where input depth data407 (e.g., denoted by Z_(I)(n)) are translated to reference depth data414 (e.g., denoted by Z_(R)(n)) for a reference display used during thepost-production process. This process is typically semi-automated withsome input 406 from the original artists (director, cinematographer,etc.) to preserve the director's intent. This process may also includeadditional processing steps (not shown), such as color grading, or colormapping from an enhanced or high dynamic range to a lower dynamic range.In one embodiment of 3D content post-production and distribution (400A),output of step 410 may comprise output reference depth data 414 (e.g.,Z_(R)(n)) generated using a depth-range conversion function (e.g.,denoted by f_(CR)(Z), such that output 414 Z_(R)(n)=f_(CR)(Z_(I)(n)). Inan embodiment, an output of process 410 may also include arepresentation of the display QVE mapping 412 (e.g., denoted asf_(QR)(Z)) for the reference display used to generate reference depthmap data 414. Reference display QVE mapping 412 may be transmitted alongwith depth data 414 as metadata along with other metadata. Referencedisplay QVE mapping 412 may be transmitted in a variety of ways known inthe art, such as a look-up table, as parameters of a parametric linear,piece-wise linear, or non-linear function, and the like, so that it maybe reconstructed by a downstream processing step, such as depthconverter 420.

Given the reference display QVE mapping 412 (e.g., f_(QR)(Z)) andreference depth data 414 (e.g., Z_(R)(n)), depth converter 420 cantranslate the depth data 414 to QVE values 424 (e.g., denoted byQ_(R)(n)) according to the QVE mapping 412 (e.g.,Q_(R)(n)=f_(QR)(Z_(R)(n))). In some embodiments, step 420 may be part ofthe encoder or transmitter that broadcasts QVE values 424 to a suitablereceiver, such as a set-top box receiver or a 3D TV. In such a scenario,bitstream 424 already incorporates information related to the referencedisplay QVE mapping and no other information needs to be transmitted. Insome other embodiments, step 420 may be part of a decoder, such as aset-top box receiver or a 3D TV. In such a scenario, the encoder needsto transmit both reference depth data 414 and the reference display QVEmapping 412. Legacy receivers may ignore the reference display mapping412 and simply process the depth data to the best of their ability;however, as will be described next, newer decoders that are enabled tointerpret correctly the guiding QVE mapping metadata, may use them tofurther improve the display of image data 412 onto the target display(440).

Let f_(QT)(Z) denote the QVE mapping function 428 for a target display440. As noted earlier, given f_(QT)(Z) (e.g., 110B) a display processorcan easily construct its inverse f_(QT) ⁻¹(Q) which for an input VQEvalue outputs a corresponding Z value. In step 430, in a receiver, giventhe set of input QVE values 424 (e.g., Q_(R)(n)), the final targetdisplay depth data 432 (e.g., denoted by Z_(T)(n)) may be generated as

Z _(T)(n)=f _(QT) ⁻¹(Q _(R)(n)).  (4)

FIG. 4B depicts an alternative embodiment for guided display adaptation.

Similarly to process 400A, step 410 in 400B generates depth datatargeting a class of displays; however, instead of outputting the outputdepth data itself (e.g., Z_(R)(n) 414) and the reference display QVEmapping 412, step 410 outputs the original depth data 407 (e.g.,Z_(I)(n)) and a representation of the depth-range conversion function(f_(CR)(Z)), such that Z_(R)(n)=f_(CR)(Z_(I)(n)).

Given Z_(I)(n) 407, f_(CR)(Z), and the reference display QVE mapping 412(f_(QR)(Z), step 420 may generate a mapping function 422 f_(QR) _(—)_(A)(Z) representing the artist's intent so that Q_(R)(n) 424 may beexpressed as Q_(R)(n)=f_(QR) _(—) _(A)(Z_(I)(n)). In an embodiment, arepresentation of mapping function 422 f_(QR) _(—) _(A)(Z) may besignaled from a transmitter or encoder to a downstream decoder usingmetadata along with depth data 407. Mapping function 422 may betransmitted in a variety of ways known in the art, such as a look-uptable, as parameters of a parametric linear, piece-wise linear, ornon-linear function, and the like, so that it may be reconstructed by adownstream processing step, such as QVE data to depth converter 430.

Given Z_(I)(n) 407, f_(QR) _(—) _(A)(Z) 422, and target display QVEmapping 428 (f_(QT)(Z)), as explained earlier, process 430 may generatethe final Z_(T)(n) depth data 432 as follows:

Q _(R)(n)=f _(QR) _(—) _(A)(Z _(I)(n)),

Z _(T)(n)=f _(QT) ⁻¹(Q _(R)(n))

In some embodiments, the depth data conversion function 416 (f_(CR)(Z))generated in step 410 may also be transmitted to a receiver in additionto the f_(QR) _(—) _(A)(Z) function 422. This will allow legacy decoderswith no concept of QVE mapping to be able to reconstruct Z_(T)(n) asZ_(T)(n)=f_(CR)(Z_(I)(n)).

In some embodiments, to preserve bandwidth and minimize the transmitteddata rate, a transmitter may transmit only a partial representation ofthe artist's mapping function f_(QR) _(—) _(A)(Z) function. Then adecoder may reconstruct a close approximation of f_(QR) _(—) _(A)(Z). Inthe context of this document, the use of an exact or approximate versionof f_(QR) _(—) _(A)(Z) is the same and inter-changeable.

Display Emulation

In some embodiments, during the content creation stage 410, a family ofQVE mapping functions 408 may be used to emulate viewing conditions ondifferent target displays using a single reference display 540. In anembodiment, FIG. 5 depicts an example process for 3D display emulation.Process 500 is similar to process 400A, except that processing steps 420and 430 may now be integrated into the single step of display emulation520.

During post-production 500, the artist 406 may use display 540 as areference display to generate reference depth data 414. During thisprocessing stage, the display emulation process 520 may be bypassed anddisplay 540 may display the color graded image content 512 baseddirectly on reference depth data 414. In case the artist wants toemulate how the output 414 will be viewed in another display (witheither a known or future QVE mapping function of a futuristic display),then display 540 may be fed depth data as generated by display emulation520, which simply combines steps 420 and 430 described earlier as partof process 400A. Under the display emulation mode, QVE mapping function428 represents the QVE mapping for the target emulated display.

Table 1 summarizes key symbols and nomenclature used herein.

TABLE 1 Key Symbols and Nomenclature Symbol Definition Comments Z_(I)(n)Original input depth All Z depth values may also be map expressed interms of disparity D values within a [d_(min), d_(max)] range and viceversa. Z_(R)(n) Reference depth map Z_(R)(n) = f_(CR)(Z_(I)(n));generated with artist's input f_(CR)(Z) Depth-map conversion Z_(R)(n) =f_(CR)(Z_(I)(n)) function f_(QR)(Z) Reference display QVE Maps Z valuesto display-specific mapping function QVE values f_(QT)(Z) Target displayQVE mapping function Q_(R)(n) QVE reference data Q_(R)(n) =f_(QR)(Z_(R)(n)) f_(QR) _(—) _(A)(Z) Artist's QVE Q_(R)(n) = f_(QR) _(—)_(A)(Z_(I)(n)) conversion function f¹ _(QT)(Q) Target display inverseMaps QVE values to QVE mapping function display-specific Z valuesZ_(T)(n) Target display depth Z_(T)(n) = f¹ _(QT)(Q_(R)(n)) map

Example Computer System Implementation

Embodiments of the present invention may be implemented with a computersystem, systems configured in electronic circuitry and components, anintegrated circuit (IC) device such as a microcontroller, a fieldprogrammable gate array (FPGA), or another configurable or programmablelogic device (PLD), a discrete time or digital signal processor (DSP),an application specific IC (ASIC), and/or apparatus that includes one ormore of such systems, devices or components. The computer and/or IC mayperform, control or execute instructions relating to guided 3D displayadaptation, such as those described herein. The computer and/or IC maycompute any of a variety of parameters or values that relate to guided3D display adaptation as described herein. The guided 3D displayadaptation embodiments may be implemented in hardware, software,firmware and various combinations thereof.

Certain implementations of the invention comprise computer processorswhich execute software instructions which cause the processors toperform a method of the invention. For example, one or more processorsin a display, an encoder, a set top box, a transcoder or the like mayimplement methods for guided 3D display adaptation as described above byexecuting software instructions in a program memory accessible to theprocessors. The invention may also be provided in the form of a programproduct. The program product may comprise any medium which carries a setof computer-readable signals comprising instructions which, whenexecuted by a data processor, cause the data processor to execute amethod of the invention. Program products according to the invention maybe in any of a wide variety of forms. The program product may comprise,for example, physical media such as magnetic data storage mediaincluding floppy diskettes, hard disk drives, optical data storage mediaincluding CD ROMs, DVDs, electronic data storage media including ROMs,flash RAM, or the like. The computer-readable signals on the programproduct may optionally be compressed or encrypted.

Where a component (e.g. a software module, processor, assembly, device,circuit, etc.) is referred to above, unless otherwise indicated,reference to that component (including a reference to a “means”) shouldbe interpreted as including as equivalents of that component anycomponent which performs the function of the described component (e.g.,that is functionally equivalent), including components which are notstructurally equivalent to the disclosed structure which performs thefunction in the illustrated example embodiments of the invention.

EQUIVALENTS, EXTENSIONS, ALTERNATIVES AND MISCELLANEOUS

Example embodiments that relate to guided 3D display adaptation are thusdescribed. In the foregoing specification, embodiments of the presentinvention have been described with reference to numerous specificdetails that may vary from implementation to implementation. Thus, thesole and exclusive indicator of what is the invention, and is intendedby the applicants to be the invention, is the set as recited in Claimsthat issue from this application, in the specific form in which suchclaims issue, including any subsequent correction. Any definitionsexpressly set forth herein for terms contained in such claims shallgovern the meaning of such terms as used in the claims. Hence, nolimitation, element, property, feature, advantage or attribute that isnot expressly recited in a claim should limit the scope of such claim inany way. The specification and drawings are, accordingly, to be regardedin an illustrative rather than a restrictive sense.

1-23. (canceled)
 24. A method to characterize a 3D display using aquality of viewing experience (QVE) mapping, the method comprising: foreach value of input depth values of a depth range or for each value ofinput disparity values from a disparity range for stereo images to bedisplayed on the 3D display, generating a corresponding output QVEdisplay value for the 3D display.
 25. Method as claimed in claim 24,generating a quality of viewing experience (QVE) mapping between theinput depth values or input disparity values and the generated outputQVE display values.
 26. Method as claimed in claim 25, comprising: foreach value of input depth values of a depth range or for each value ofinput disparity values from a disparity range for stereo images to bedisplayed on a reference 3D display, generating a corresponding outputQVE reference display value for the reference 3D display; generating areference QVE mapping between the input depth values or input disparityvalues and the generated output QVE display values.
 27. The method ofclaim 24, wherein generating the QVE display value comprises: displaying(210) on the 3D display a test stereo image with the input depth ordisparity; capturing the displayed image with a camera to generate a 2Dcaptured image (215); and analyzing the 2D captured image to generatethe output QVE value corresponding to the input depth or disparity(220).
 28. The method of claim 24, wherein the quality of viewingexperience comprises a measure of visual blur.
 29. The method of claim28, wherein a view of the test stereo image comprises one or more 2Drepresentations of a sinusoid function.
 30. The method of claim 27,wherein analyzing the 2D capture image comprises: generating a set ofblurred images with a blur filter in response to a view of the teststereo image, wherein each blurred image in the set of blurred image isgenerated using a different blur parameter; comparing the 2D capturedimage to one or more of the blurred images in the set of blurred imagesto determine one or more difference metrics according to an imagecomparison criterion; and generating the output QVE value in response tothe one or more determined difference metrics.
 31. The method of claim30, wherein the blur filter comprises a Gaussian filter, the blurparameter comprises the standard deviation of the Gaussian filter, andthe output QVE value is a function of the standard deviation of theGaussian filter for which the difference metric between its output andthe 2D captured image is the smallest.
 32. A method for guided 3Ddisplay adaptation, the method comprising: receiving original inputdepth data (407) for a stereoscopic image; generating reference depthmap data (414), the reference depth map data being generated in responseto the original input depth data (407) and a depth range conversionfunction (416); and generating quality of viewing experience (QVE) data(424) in response to the reference depth map data (414) and a referencedisplay QVE mapping (412), wherein the reference display QVE mappingrepresents an input-output relationship between input depth or disparityvalues and output QVE values as determined for the reference display.33. Method as claimed in claim 32, wherein the reference display QVEmapping (412) is generated in accordance with claim
 25. 34. The methodof claim 32, further comprising: generating an artist's mapping function(422), the artist's mapping function representing an input-outputrelationship between the original input depth data and the QVE data(424); and transmitting to a receiver the artist's mapping function(422) and the original input depth data (407).
 35. The method of claim32, further comprising transmitting to a receiver the QVE data (424).36. The method of claim 32, further comprising transmitting to areceiver the reference depth data (414) and a representation of thereference display QVE mapping (412).
 37. The method of claim 32, furthercomprising transmitting to a receiver the original input depth data(407), a representation of the reference display QVE mapping (412), anda representation of the depth range conversion function (416).
 38. Amethod for guided 3D display adaptation in a decoder, the methodcomprising: receiving at the decoder original input depth data (407) anda representation of an artist's mapping function (422), the artist'smapping function representing an input-output relationship between theoriginal input depth data and QVE data (424) generated by an encoder fora reference display; applying the artist's mapping function to theoriginal depth data to generate decoded QVE data; and applying to thedecoded QVE data an inverse QVE mapping for a target display (428) togenerate target depth data for the target display (432), wherein theinverse QVE mapping for the target display represents an input-outputrelationship between input QVE values and output depth values asdetermined for the target display.
 39. A method for guided 3D displayadaptation in a decoder, the method comprising: receiving at the decoderQVE data (424) generated by an encoder according to claim 35; andapplying to the QVE data an inverse QVE mapping for a target display(428) to generate target depth data for the target display, wherein theinverse QVE mapping for the target display represents an input-outputrelationship between input QVE values and output depth values asdetermined for the target display.
 40. A method for guided 3D displayadaptation in a decoder, the method comprising: receiving at the decoderreference depth data (414) and a representation of a reference displayQVE mapping (412), wherein the reference display QVE mapping representsan input-output relationship between input depth or disparity data andoutput QVE values as determined for a reference display; applying thereference display QVE mapping to the reference depth data (414) togenerate decoded QVE data; and applying to the decoded QVE data aninverse QVE mapping for a target display (428) to generate target depthdata for the target display, wherein the inverse QVE mapping for thetarget display represents an input-output relationship between input QVEvalues and output depth values as determined for the target display. 41.A method for guided 3D display adaptation in a decoder, the methodcomprising: receiving at the decoder original input depth data (407), adepth range conversion function, and a representation of a referencedisplay QVE mapping (412), wherein the reference display QVE mappingrepresents an input-output relationship between input depth or disparitydata and output QVE values as determined for a reference display;applying the depth range conversion function to the original input depthdata to generate reference depth data (414); applying the referencedisplay QVE mapping to the reference depth data (414) to generatedecoded QVE data; and applying to the decoded QVE data an inverse QVEmapping for a target display (428) to generate target depth data for thetarget display, wherein the inverse QVE mapping for the target displayrepresents an input-output relationship between input QVE values andoutput depth values as determined for the target display.
 42. A methodfor 3D display emulation, the method comprising: receiving originalinput depth data (407) for a stereoscopic image; generating referencedepth map data (414), the reference depth map data being generated inresponse to the original input depth data (407) and a depth rangeconversion function (416); generating quality of viewing experience(QVE) data (424) in response to the reference depth map data (414) and areference display QVE mapping (412), wherein the reference display QVEmapping represents an input-output relationship between input depth ordisparity data and output QVE values as determined for the referencedisplay; selecting to emulate a target display; and applying to the QVEdata (424) an inverse QVE mapping for the emulated target display (428)to generate target depth data for the emulated target display, whereinthe inverse QVE mapping for the emulated target display represents aninput-output relationship between input QVE values and output depthvalues as determined for the emulated target display.
 43. Anon-transitory computer-readable storage medium having stored thereoncomputer-executable instructions for executing a method in accordancewith claim
 24. 44. A method to characterize a 3D display using a qualityof viewing experience (QVE) mapping, the method comprising: for eachvalue of input depth values of a depth range or for each value of inputdisparity values from a disparity range for stereo images to bedisplayed on the 3D display, generating a corresponding output QVEdisplay value for the 3D display, wherein generating the QVE displayvalue comprises: displaying (210) on the 3D display a test stereo imagewith the input depth or disparity; capturing the displayed image with acamera to generate a 2D captured image (215); and analyzing the 2Dcaptured image to generate the output QVE value corresponding to theinput depth or disparity (220), wherein analyzing the 2D capture imagecomprises: generating a set of blurred images with a blur filter inresponse to a view of the test stereo image, wherein each blurred imagein the set of blurred image is generated using a different blurparameter; comparing the 2D captured image to one or more of the blurredimages in the set of blurred images to determine one or more differencemetrics according to an image comparison criterion; and generating theoutput QVE value in response to the one or more determined differencemetrics.